1. Field of the Invention
This invention relates to an automatic tape cassette selecting and loading device adapted for sequential and selective loading of a large number of tape cassettes into video tape recorders operable in at least the reproducing mode with a view to achieving continuous video reproduction for an extended period of time.
2. Description of the Prior Art
There has been used in, for example, a broadcasting station, an automatic cassette loading device in which a large number of tape cassettes are automatically selectively loaded in sequence into a video tape recorder, heretofore abbreviated to VTR, in order to perform a continuous video reproducing and/or video recording for an extended time.
A known automatic cassette loading device of this type, for example, as shown in FIGS. 1,2 and 3, comprises a vertical cassette storage rack 352 containing a large number of tape cassettes 351. On the back side of cassette storage rack 352 is disposed a cassette transfer unit 353, and in back of the latter are arranged, in vertical tiers, a plurality of VTRs 354 each operable in at least the reproducing mode. The cassette storage rack 352 is formed by cassette storing shelf sections 355 for storing the tape cassettes 351 in vertical tiers and horizontal rows. The cassette transfer unit 353 is designed to be moved along these numerous cassette storing shelf sections 355 between the cassette storage rack 352 and the VTR 354 in the vertical direction (indicated by an arrow Y) or in the horizontal direction (indicated by an arrow X).
As shown in FIGS. 2 and 3, the cassette transfer unit 353 has a lower cassette transfer passage 356 and an upper cassette transfer passage 357. During loading of a cassette into a VTR 354, a tape cassette 351 is charged into transfer passage 356 of transfer unit 353 from within a selected cassette storing shelf section 352 in the direction of an arrow a, as shown in FIG. 2. The cassette transfer unit 353 is then moved in the direction of an arrow b to a particular VTR 354, and the tape cassette 351 is then discharged in the direction of an arrow c so as to be loaded from within transfer passage 356 into registered VTR 354. When taking the cassette out of the VTR 354, the tape cassette 351 is fed in the direction of an arrow c' (FIG. 3) from the VTR 354 into the other or upper cassette transfer passage 357 of the cassette transfer unit 353, and the cassette transfer unit 353 is then moved in the direction of an arrow b' to the original cassette storing shelf section 355 of the cassette storage rack 352, whereupon the tape cassette 351 is returned in the direction of an arrow a' from cassette transfer passage 357 into the original cassette storing shelf section 355, as shown in FIG. 3.
In the above described conventional automatic cassette loading device, the cassette storage rack 352 for storing the tape cassettes 351, the cassette transfer unit 353 and the VTRs 354 arranged in plural tiers, are grouped together into a single device. For this reason, it is necessary to increase the size of the cassette storage rack 352 if it is desired to increase the storable number of tape cassettes 351.
However, if the size of the cassette storage rack 352 is increased to increase the storable number of tape cassettes 351, a prolonged operating time is required for effecting the operations incident to exchanging the tape cassette disposed in each VTR. More particularly, when the size of rack 352 is increased, increased times are required for seeking out a specified cassette 351 in rack 352, loading the cassette into a VTR 354, and returning cassettes from other VTRs to the respective shelf sections 355 of rack 352. The result is that it becomes difficult to achieve continuous or uninterrupted video reproduction by using plural VTRs 354. More particularly, since the VTRs 354 are used at broadcasting stations by switching from one to another of the VTRs 354 at intervals comprised of tens of seconds, it becomes impossible to effect continuous video reproduction when the operating time for exchanging the cassettes in such VTRs is prolonged.
In addition, when the size of cassette storage rack 352 is increased, the overall device is enlarged in size, so that difficulties are presented in its transportation and installation. Further, the known device is not adaptable to being arranged in block form for assembly of the several blocks at the site of eventual use.